1. Field of the Invention
The present invention relates to an air gun for firing bullets using supplied compressed gas, and for carrying out blowback in order to move a slide towards the rear of the gun to fire the next bullet.
2. Description of the Related Art
With a related art air gun for carrying out blowback in order to shoot the next bullet, supply of compressed gas to the air gun for shooting the bullet using the compressed gas is carried out by a gun comprised of a compressed gas chamber for storing compressed gas, an opening and closing valve for carrying out release of compressed gas in order to fire a bullet, and a switching valve for switching a discharge destination for compressed gas supplied by opening the opening and closing valve, the opening and closing valve being provided inside a handle and opened by striking a valve rod on a hammer to supply compressed gas inside the compressed gas chamber, the switching valve being provided in a slider section or handle and switching the discharge destination of the compressed gas supplied by opening the opening and closing valve.
That is, an automatic air gun of the related art that uses compressed carbon dioxide gas or air is known, for example, such as the air gun shown in FIG. 22 (related art 1).
Related art one, which is an air gin of the related art, will be described in the following. Numeral 401 indicates an air gun. Operation of the air gun 401 will be described in the following, but up to where a bullet W is supported inside a rubber chamber 408 and the bullet W itself fired, from a state where an exchange valve 409 is moved to the rear of the air gun 401 against urging force of a valve spring 412 will be described. First of all, a trigger 402 for firing the bullet W is pulled. In doing so, a hammer 403 rotates in the direction shown by an arrow, and presses down a valve pin 404. By pressing down the valve pin 404 the valve 406 is opened, compressed gas stored in an accumulator chamber 405 passes through the valve 406 and flows to the slide 407 side. The exchange valve 409 at this time blocks off a cylinder 413 side so that no compressed air flows out to the cylinder 413 side.
Compressed gas that flows in to the slide 407 side flows in to the side of a bullet W inside the rubber chamber 408, pressing the bullet W out, passing through the inside of an outer barrel 410 to be fired with force from the muzzle.
After firing the bullet W, since there is no longer a bullet W in the rubber chamber 408 the exchange valve 409 is pressed back to the muzzle side (not shown in the drawing) by the force of the valve spring 412, flowing out of compressed gas to the muzzle side is prevented, and the cylinder side is opened. As a result, compressed gas that has been prevented from flowing out to the muzzle side flows to the inside of the cylinder 413, the cylinder 413 and the slide 407 are moved to the rear of the air gun 401 against the urging force of the slide spring 414, moving the hammer 403 rearwards, and when returned to the muzzle side, a muzzle side tip of the slide 407 presses the next bullet supplied from a magazine 411, loads the bullet into the rubber chamber 408, and carries out preparation for firing of the next bullet.
Also, an air gun 501 of related art 2 shown in FIG. 23 is as follows.
501 is an air gun. In the following the operation of the air gun 501 will be described, but description is from a state where a bullet W is supported inside a loading packing 508. With this second related art, an exchange valve 509 is different from that of the first related art, and in a state where a bullet W has been loaded into the loading packing 508, it is possible for compressed gas stored in an accumulator chamber 505 to flow out to the side of a bullet W loaded in the loading packing 509 in a normal state without pressing the bullet, and no air flows out to the cylinder 513 side. Then, after firing the bullet W, in the event that compressed gas flows out rapidly to the muzzle (not shown) side, the exchange valve 509 is moved in the muzzle direction by this negative pressure, a piston block 507 side is blocked off, and the cylinder 513 is opened, moving so that compressed gas flows out to the cylinder 513 side.
First of all, the trigger 502 is pulled in order to fire the bullet W. In doing so, a hammer 503 rotates in the direction shown by the arrow, and presses a valve rod 504. The valve 506 is opened as a result of the valve rod 504 being pressed, and compressed gas stored in the accumulator chamber 505 flows through the valve 506 to a piston block 507 side. Inside the piston block 507, an exchange valve 509 puts a loading packing 508 side in an open state using urging force of a spring 512, and a side end portion of the exchange valve 509 to the rear of the air gun 501 blocks of the cylinder 513 side, which means that compressed gas that has flowed to the piston block 507 side flows to the bullet W side inside the loading packing 508, which means that the bullet W is forced out, passes inside the outer barrel 510 and is fired with force from the muzzle.
After the bullet W has been fired, since there is no longer a bullet W in the loading packing 508 compressed gas flows rapidly to the loading packing 508 side, the exchange valve 509 is pressed back to the muzzle (not shown) side against the urging force of the valve spring 512 by negative pressure generated by compressed gas flow, and outflow of compressed gas to the muzzle side is prevented. Accordingly, compressed gas that has been prevented from flowing out to the muzzle side flows to the inside of the piston block 507, the piston block 507 is moved to the rear of the air gun 501, moving the hammer 503 rearwards, and when returned to the muzzle side, a muzzle side tip of the piston block 507 presses the next bullet supplied from a magazine 511, loads the bullet into the loading packing 508, and carries out preparation for firing of the next bullet.
As described above, the air guns of related art 1 and related art 2 the next bullet is supplied by changing whether compressed gas flows from a muzzle side at an upper part of the air gun to a muzzle side inside a slide provided capable of reciprocal sliding to the rear of the gun, or flows to the rear of the gun, but an exchange valve for changing the flow path of the compressed gas is provided inside a slide capable of sliding at an upper part of the air gun.
Further, air guns of the related art using compressed gas are shown in U.S. Pat. No. 2,817,328 and U.S. Pat. No. 5,476,087. With these air guns, a valve for carrying out discharge of compressed gas in order to fire a bullet, and a mechanism for carrying out bullet loading and preparation for firing of the next bullet, exist separately.
In this way, with the related art method, an opening and closing valve for supplying compressed gas, and an exchange valve or mechanism for cutting off supply of compressed air to a bullet side after the bullet has been loaded and preparing to fire a bullet, so that compressed gas is supplied in order to move a cylinder etc. to the rear of the gun, are each provided separately.
However, with the related art method, since the opening and closing valve and the exchange valve are provided separately, there is an increase in the number of component parts, as well as it becoming difficult to miniaturize the overall structure, there is a problem that wasteful use is made of compressed gas to the extend of the volume of compressed gas passing between each of the valves, and it is difficult to unite the two to miniaturize the gun.
In view of these problems, an object of the present invention is to reduce the size of functions of an opening and closing valve and an exchange valve to improve compressed gas usage efficiency, and to enable miniaturization of an air gun.
The inventors of this application have also invented an air gun (related art 3) as described in the following, to solve the above described problems of the related art, and acquired a patent, namely U.S. Pat. No. 6,026,797, which was applied for in America on Sep. 25, 1998.
American patent No. 6,026,797 shown in FIG. 24 will be described in the following.
The air gun of U.S. Pat. No. 6,026,797 can provide a valve that is compact in function and improves usage efficiency of compressed gas. To achieve this, the air gun is constructed with a hit pin arranged in a cylinder portion, a valve body arranged within a hollow portion of the cylinder portion and having a bullet supplying nozzle chamber and a valve pin chamber, a gas inlet port opened to a sleeve-shaped circumferential face of the valve pin chamber, a bullet supplying nozzle arranged within the bullet supplying nozzle chamber, and a valve pin arranged within the valve pin chamber. The hit pin is pressed on a muzzle side and the valve pin is made to slide to the muzzle side so that an air-tight state between a valve pin flange portion and a side face of the valve pin chamber on its gun rear end side is released. A compressed gas is supplied to a nozzle chamber side opening and a valve pin chamber side opening from a clearance between the valve pin flange portion and the gun rear end side face of the valve pin chamber.
However, the air gun of related art 3 is operated by compressed gas, and compressed gas starts to cause the slider to retreat before compressed gas starts to cause the bullet to move inside the barrel. Therefore, start of movement of the bullet and firing are delayed more than retreating movement of the slide. Because of this slide retreating, it is easy for the valve to move up and down, particularly in a downward direction, and there is a problem that shooting precision is lowered.
Also, the air gun of related art 3 causes operation of a bullet supply nozzle using high pressure compressed gas, and as a result of repeating this operation there may be occasions when problems with durability arise.